Hi Stephan. We generally try to follow development of the master branch of the X server closely and we do have support for it in our development codebase, but there are a lot of factors that contribute to when we can release betas. I'm afraid I can't give you an ETA on when a driver with those changes.

I can't make any promises, but if you sign up for the registered developer program, there's a chance we could give you early builds under NDA, if that's okay with you.